25 Interviews for the FNP’s 25th Anniversary: prof. Krzysztof Jóźwiak, a chemist involved in molecular pharmacology, talks to Patrycja Dołowy

Dodano: :: Kategorie: 25 years Foundation for Polish Science
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The Foundation for Polish Science (FNP) celebrates its 25th anniversary this year. To mark the occasion, we have invited 25 beneficiaries of our programmes to tell us about how they “practise” science. What fascinates them? What is so exciting, compelling and important in their particular field that they have decided to devote a major part of their lives to it? How does one achieve success?

The interviewees are researchers representing many very different fields, at different stages of their scientific careers, with diverse experience. But they have one thing in common: they practise science of the highest world standard, they have impressive achievements to their credit and different kinds of FNP support in their extensive CVs. We are launching the publication of our cycle; successive interviews will appear regularly on the FNP website.

Pleasant reading!

Science Non-Fiction

Prof. Krzysztof Jóźwiak, a chemist involved in molecular pharmacology, talks to Patrycja Dołowy.

PATRYCJA DOŁOWY: You are head of the Department of Biopharmacy at the Medical University of Lublin, a chemist by education, a professor of pharmaceutical sciences, a recipient of prestigious awards. And, you combine different areas in an extremely comprehensive way.

KRZYSZTOF JÓŹWIAK: I am fascinated by what life is like at the molecular level. Life is cells which are in interaction with one another. We are able more and more often to translate these interactions into specific chemical or biophysical processes, answer questions about what goes on in cells, which are well programmed, extremely complicated reactors. My interest in drugs emerged when I was still a student. From a chemist’s point of view it is surprising that a few milligrams of a substance can cause such serious changes (halting an undesirable process or inducing a desirable one) in the whole body. In the beginning, the most incredible discovery was that drug molecules had partners in the body – now these are my molecular targets. They are most often proteins fulfilling specific and important functions. Changes in their functioning are a source of serious symptoms that we observe on a macroscopic scale as disease pathologies in patients. Meanwhile, it all happens at the level of cells, molecules, processes occurring there. Microorganisms causing infections are also cells. If we want to eliminate them, we find molecular targets within them, the best ones being those that don’t exist in our body, and hit them directly with a substance that neutralizes the target and thus the whole pathogen.

And doesn’t harm us.

In this case, there’s still a long way ahead. Treatment, even in today’s medicine, is still a matter of balancing profits and losses. Every intervention is linked to risk in some way. We do our best to identify and eliminate them. Understanding the processes that fascinate me began shortly before I became a scientist. I really enjoyed following successive scientific reports enabling me to delve into the world of macromolecules – how they function, how they interact with one another. I was interested to find out whether, how and where a drug molecule can manipulate a given process: suppress it, reinforce it, redirect it. If you asked me only about fundamental research, I could stop here. You practise science out of a desire for knowledge.

Is that enough?

It could be a sufficient driving force. But there’s also the matter of application. Knowing that we have the results of many years of fundamental research in front of us, we think about applications. Also when we apply for grants. Once we understand molecular processes well, we can propose new substances that will act on a specific enzyme in a specific location. These can be completely new drugs, though actually I most often try to improve what already exists. We work on how to modify a molecule so it works better, has better selectivity, focuses more on a specific protein target. On many occasions we have been able to propose already known molecules used in other therapies for effective application in a new area. A neurologist is interested in the brain and neurons, a cardiologist in the effects on the heart. Meanwhile, similar molecular processes take place in different cells and tissues. Their effects may be different, but they are based on similar biochemical routes.

So before we give patients a drug we have to check at the level of the whole body how it affects cells in other systems?

This is always a problem. I’m a chemist, so to me a patient is a set of biochemical processes that we want to change and understand – a set of molecular targets for drugs. From a medical point of view all this happens at a higher, more complicated level. For example, we can predict what will happen in a neuron when we block a given effector. We know what processes occur there and we understand them. However, it gets very complicated at the brain level. And it often causes us to review our initial plans – eliminating planned research projects. Probably all scientists in my field have stories of failure, when it turns out that a substance that works great in the laboratory at the molecular, cellular, and even in vitro tissue level, won’t work in animal models. Or, it works in animals but then won’t work in people. It can also happen that it’s only after a substance is used on people that side effects come to light about which a mouse was unable to tell us.

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Pictured: prof. dr. hab. n. farm. Krzysztof Jóźwiak, photo by Magdalena Wiśniewska-Krasińska

Is there anything that interests you the most?

Processes occurring in the nervous system. Neurons communicate with one another through synapses. They send neurotransmitters for which there are appropriate receptors at the opposite end of the synapse. The activation of receptors induces biological processes in the cell, the signals most often undergo very strong reinforcement. Stimulation of one or several synapses can cause the biochemistry at the level of the whole cell to change – at the level of the nerve fibre the signal can be transmitted further along. Or not. In many therapies, not just neurological ones, neuronal receptors are important molecular targets.

Which ones for example?

One of our flagship projects studies substances that could very selectively act on β-adrenergic receptors. These are receptors in the cell membrane whose stimulation in the body by adrenalin or a similar substance is tied to activation of so-called G proteins and in effect to regulation of activity that is important to a cell’s functioning. These receptors take part in neural transmission, but they also have a therapeutic effect in treating asthma or circulatory diseases. Drugs acting on these receptors have been known and used for a long time; this field has been exhausted. But we investigated a modification of well-known substances making their action super-selective towards one of the receptor subtypes. We were interested in its special application in congestive heart failure. That was what the first grant was for. We were successful, but in addition it turned out that the newly obtained substances unexpectedly showed some very puzzling action in a completely different area. They effectively restricted cancer cell proliferation, of course only for some cellular lines.

It’s incredible how complicated it all is!

When you work with a whole base of chemical substances similar in shape and similar in structure, their analysis shows that acting at a very specialized site, even though they act on the same receptor, these substances can induce completely different processes. For example, one of our substances acts on the β receptor subtype I mentioned, but also on another receptor – one linked to G proteins, until recently considered to be an orphan receptor (we were unable to assign a partner and function to it), generating anticancer actions. We will have to take this into account. The method was very effective during in vitro research on dozens of different cellular lines. When the substance was given to animals it significantly diminished cancerous tumour growth. I am carrying out this project in collaboration with scientists from the National Institutes of Health (NIH) in the United States. The next stages of preclinical trials require greater commitment and financial outlays. A pharmaceutical company has taken over licensing of our substance. So, we are leaving the level that I am interested in the most, namely molecules, and moving to the level of tissues, animal models and soon, I hope, clinical trials. At the same time, we are working on projects focusing on other receptors and proteins related to neural transmission.

It sounds cosmic. Every substance acts on many different planes. It’s tempting not to investigate this individually but to work in large teams.

We have managed to build a team comprising researchers from Poland and from abroad. We have completed and are working on a number of projects with a chance of success. Some paths turned out to be blind alleys. We are still developing others. One large project resulted from our interest in a nicotinic receptor. It is an ion channel activated by acetylcholine – our natural neurotransmitter. This receptor is not widely used in pharmacology, though of course it is “used” by smokers. Until recently it was not considered a molecular target in therapies. Now it turns out that it offers possibilities in treating depression or dementia. Alzheimer’s disease involves, among other things, the selective death of cholinergic neurons. Thus, a substance that would improve cholinergic activity could be effective in therapy. Such substances are being identified – a few drugs have even been introduced to the market. Most of them act on an enzyme that decomposes acetylcholine. The drugs suppress the enzyme, the concentration in the inter-synaptic spaces increases, and therefore communication between neurons is more efficient. We are looking for a substance that would sensitize the receptors to appearing acetylcholine. Then, even if its concentration was lower the receptors would still do their job.

Does this mean nicotinic receptors could be useful here?

Memory deficits are very complex and involve many biochemical processes. For now, we are trying to develop drugs acting on a specific receptor, e.g. a nicotinic receptor. But there are many more potential molecular targets. In another project, we are working on positive modulators of one of the glutamatergic receptors – AMPA. We already know substances that act on these receptors and they can be used to improve concentration.

How is it with nicotine, then? It’s a poison on one hand, but on the other it can be used to improve memory?

This may not sound very good for educational purposes, but there is research showing that tobacco smokers get Alzheimer’s less often. The results are debatable, depending on what other factors are taken into account. Some researchers are inclined to support this hypothesis while others are against it. Nevertheless, it seems possible that long-term stimulation of nicotinic receptors strengthens cholinergic neurons, making them work better. And even if the biochemical processes linked to the disease continue to progress, their effect is smaller. Others say with some irony that smokers get Alzheimer’s less often simply because they seldom stand a chance of living to the appropriate age. In any case, there are research results pointing to nicotine’s complicated mechanism of action in this disease.

It’s incredible that such an apparently poisonous substance could be helpful.

Nicotine acts on the same receptor for which acetylcholine is a natural ligand (partner). If a chemist looks at the biochemical structures of these substances, he will see a similarity. And here we come to an interesting issue. What do chemists do in pharmacology? They look for similarities! Between natural substances like neurotransmitters, about which we know how they act, and other substances occurring in nature. In the course of evolution many organisms produced substances that are used as a poison or a deterrent against aggressors. The tobacco plant most probably produced nicotine to protect its leaves from being eaten. It failed with humans. Humans are a species who like using various slightly poisonous substances to change their behaviour or perception. But insect caterpillars, which have acetylcholine receptors similar to ours, spare the tobacco leaves exactly because of this. Actually, there is a whole range of insecticides in which nicotine analogues are the active substances.

Does this mean these substances are biochemically similar, reacting similarly with receptors, but at the level of the cell or the whole organism they act completely differently?

Nicotinic receptors in the body are used not just in communication between neurons but also in transmitting signals from the neuronal system to the neuromuscular junction. Many poisonous animals and plants take advantage of this, producing substances with similar biochemical action. A poisonous snake hunting a mouse uses a substance which, for example, blocks nicotinic receptors, immobilizing the prey. Humanity has also learned to take advantage of this, and recently even to use such substances in clinical practice. Pavulon, for example, which a few years ago gained notoriety (not proven in court) in the case of the “skin hunters”, contains the active substance pancuronium, which was isolated from the naturally obtained poison curare. Indians used it to incapacitate the animals they hunted. We use it as a muscle relaxant, which can be useful when we want to prepare a patient for surgery, for example.

If it acts in one direction, it could probably act in another – for example helping treat addictions?

One of our projects involved studying substances that could modulate nicotinic receptors to make them less sensitive to nicotine. The market has already seen drugs with this kind of action being advertised intensely in the media (interestingly, they also contain a nicotine analogue thanks to which a certain plant defends itself against intruders). Along the same lines, you can fight against other chemical addictions, e.g. to morphine or heroin, using substances that induce the appropriate receptors but do not cause such strong addiction. If someone is a heroin addict and seeks stimulation, instead of heroin whose use leads to serious consequences, it’s better if they use methadone or buprenorphine which act on the same receptor. They activate it, pretend to do what heroin does, but their action is weaker so by reducing the dosage over a period of time, it is easier to get people out of behaviours linked to addiction. Actually, this illustrates a very interesting issue. It was believed until recently that receptors were one-dimensional switches. That we had the cell membrane and the receptor, a neurotransmitter acted on one side of the membrane, click: a specific cellular process was activated, the signal was strengthened and in the end there was the effect. Meanwhile, it turns out that it’s much more complicated. Depending on the molecule with which it is stimulated, one receptor can activate different alternative signal pathways in the cell, which can lead to different effects. It is currently believed that this could be the basis of methadone treatment. Heroin, or rather its active metabolite in the body, morphine, activates at least two signal routes. One is linked to strong stimulation in the brain reward system while the other seems to be related to building addiction. Methadone only activates the first of these routes. We stimulate the reward system but do not strengthen addiction processes.

Clever…

We’ve come to a different level of resolution. This is one of the most interesting problems in current neuropharmacology and medicinal chemistry. Until recently it was considered obvious that using two different drugs blocking the same molecular target should lead to the same effects. Now we know it isn’t always true. Attention is now being paid to the activation of alternative signal pathways in cells through stimulation of the same receptor. This has been a hot topic for about ten years.

I’m not surprised by the temptation to combine so many directions and levels. Is this what you are doing thanks to a grant from the Foundation for Polish Science?

New dimensions emerge as research progresses – that is the whole beauty of science. An answer to one question generates three more, often in other research areas. That is the way I want to think about a scientific project: building a team of people who, having experience from different fields, communicating with one another, could handle at least some of those dimensions. Structural research, protein modelling and analyses of their interaction with drugs generate questions that need to be checked experimentally. On the other hand, experiments on animals, for example, suggest questions which we can answer at the molecular level. Of course in the end we are interested in the action of drugs at the level of a patient’s body. However, a problem that is starting to interest me particularly is the action of drugs at the societal level. There have been some initial reports about drugs influencing interactions between people. These are fascinating observations and perhaps in a while we’ll be able to talk about this in more detail.

All this creates opportunities for collaboration among scientists.

At my lab we combine bioinformatics, structural biology with cellular biology and research on animal models. But thanks to the FNP’s TEAM programme we have gone even further and have been able to join an international consortium that is working successfully on a large research project. I work with leading specialists from different fields of research. The most important but also the hardest thing in this work is communication, because every field uses its own esoteric language code. Two people seem to be talking about the same thing but use such different languages that they don’t understand each other. It took us a long time to work out methods of communication. And I don’t mean English, which is not our native language! But when you talk, there turn out to be points of contact that can lead to new hypotheses, ideas, applications. I’ve always believed that the most fascinating  things in science happen at the junction of different disciplines. Disciplinarity is restrictive. My PhD students visit our partners, learn completely new techniques and how to conduct research in new areas, and they also watch how projects are managed in different institutions and countries.

New team, your own place, new challenges. Was this a big change?

The FNP changed a great deal in my life. It gave me a lot of support at different stages of my development. It was thanks to the foundation that I was able to find some great people. I’m convinced that the best of the best came to work with me in Lublin, and everything that’s happening now only confirms this. However, I value the foundation the most for being an institution that consistently raises and sets new standards. I remember a discussion quite a few years ago, with a professor who said you couldn’t pay PhD students as much as 3,000 zlotys monthly as a stipend because it was unethical. Thanks to the foundation this way of thinking has changed. By now everyone has accepted that stipends in grants, also those financed by the NCN or NCBiR, have to be decent. If someone works on a project that received funding in a harsh competition with very strict requirements, they deserve to work and not have to worry about having enough till the end of the month without moonlighting.

Listening to you, it seems that our ideas about research from a few years ago did not come close to what science is today. Which way are things going?

Nobody knows, of course – and that’s a very scientific answer. However, we are studying increasingly complicated processes at increasing resolution, which requires increasingly accurate tools. It’s at these deeper levels that there are chances for innovation today. By discovering new mechanisms, scientists are able to propose solutions that would have been completely impossible just a few years ago, even a year ago. One example is the CRISPR-Cas9 technology, on which great hopes are pinned. It is already being used to edit genes in cells, but there are also attempts, partly successful, to use it in people suffering from rare genetic disorders.

Science ethicists should read a lot of science fiction, since it will all happen very soon.

Today’s science ethicists have to think ahead into the future. It’s worth assuming different scenarios and minimizing risk. I try to remember that the therapies we apply today will someday, in light of new knowledge, be considered outdated and inadequate. Take the story of George Washington’s death: he got tonsillitis in December 1779. He felt poorly, physicians were sent for. The president was probably attended by one of the best doctors in the country at the time. He took a look, examined him, prescribed blood letting. It didn’t help much, so another doctor was called after a while. He took a look, examined him, prescribed blood letting. Washington had 4 or 5 such visits and then died. He didn’t survive such loss of blood. Today we would consider it a completely inadequate and barbarian therapy. But at the time, these were the best doctors and they acted in accordance with their knowledge. The therapies we use today will be revised by science in the future. This is certainly what I think about chemotherapy in treating cancer. It’s like dropping an atomic bomb on a city to kill off the rats, in the hope that the people who survive will rebuild the city. Maybe doctors won’t agree with me, but in many cases we use this method because there’s not much more we know we could do. We do what we can to help patients.

And if you were to imagine what will happen next?

Understanding nature with increasing resolution, at some point we’ll be able to develop therapeutic methods targeting specific processes more selectively. That’s why I think the future of pharmacology is in biology, not chemistry. Just recently results were published from a preliminary stage of clinical trials on a monoclonal antibody that helps remove β-amyloid deposits in the brain – in a few or a dozen years this could bring a breakthrough in the treatment of Alzheimer’s disease. Those who finance research like to hear about fast, direct applications, but it doesn’t work like that. Chemistry developed from alchemy – considered a non-science – to which monarchs provided funding lured by the vision of obtaining the philosopher’s stone and gold. Meanwhile, alchemists quietly and laboriously built their retorts, distilled mixtures and performed simple reactions. And in this way, after a long time this “non-science” developed into a science – the applications that emerged were completely different from  those expected by the grant providers. Scientific progress is mind-boggling today and keeps accelerating. I have no idea where we’ll be in 10 years’ time because what we have today, we would have considered science fiction 10 years ago.

Prof. KRZYSZTOF JÓŹWIAK, (b. 1971) heads the Department of Biopharmacy at the Medical University of Lublin. A beneficiary of FNP programmes: FOCUS (2006) and TEAM (2009).